Apparatus for grinding lenses



April l, 1941. R. F. METZGER APPARATUS FOR GRINDIG LENSES Original FiledAug. 4, 1938 ATTORNEY Patented Apr. 1, 1941 UNITED STATES `PATENT OFFICE4 Claims.

This invention relates to apparatus for grinding lenses, particularly inthe production of lenses of the type and kind disclosed in my priorapplication Serial No. 204,733, filed April 28, 1938 (which has issuedas Patent No. 2,197,504 of April 16, 1940), and constitutes a divisionof my prior y application Serial No, 223,025, filed Aug. 4, 1938; andthe object of the invention is to provide an apparatus comprising agrinding wheel or disk with means adjustable transversely of the surfaceof the disk for gaging the radial depth of the grinding operation to beperformed on the peripheral edge or edges of the lens; a further objectbeing to providemean's for moistening the grinding wheel or disk and forwiping the same clean in advance of engaging the workpiece; a stillfurther object being to provide a work-piece supporting table adjacentthe grinding wheel or disk and in spaced relation to the rst namedadjustable means for supporting the lens in forming a notch or indenturein the peripheral edge of a lens at one or more points circumferentiallythereof;v and with these and other objects in view the inventionconsists in an apparatus as more fully hereinafter described andclaimed.

The invention is fully disclosed in the following specification, ofwhich the accompanying drawing forms a part, in which the separate partsof my improvement are designated by suitable reference characters ineach of the views; and in which:

Fig. 1 is an end View of one form of apparatus which I employ and withpart of the construction shown in section.

Fig. 2 is a side View showing part of the construction shown in Fig. 1,looking in the direction of the arrow 2 of Fig. 1, and omitting part ofthe construction.

Fig. 3 is a detail View of a part of a lens indicating two steps informing the coupling anges on the peripheral edges thereof; and,

Fig. 4 is a partial section on the line 4-4 o1" Fig. Son an enlargedscale.

This invention, which constitutes a division of the subject matter of myprior application Serial No. 223,025 filed August 4, 1938, deals withthe formation of reduced fianges on other peripheral edge portions oflenses and vparticularly in eyeglass lenses to adapt the samefor use inVarious kinds and classes of mountings, such for example as the type ofmounting specifically described and claimed in my prior applicationSerial No, 204,733 hereinbefore identied. Only one form lor'type of lensrconstruction is shown, it being understood that `the apparatus hereindisclosed is adaptable for use in .shaping the peripheral edges oflenses of any kind or class especially in reducing the thickness of thelenses at the peripheral edges thereof by grinding one or both sidesurfaces of the lenses and further in reducing the radial dimension ofthe lenses at the peripheral edges thereof, especially in formingprojecting, coupling or mounting iianges or elements.

In Figs. 1 and 2 of the drawing I have shown more or lessdiagrammatically one `:form of apparatus which consists in providing asuitable base plate I0 which may have a series of domes II of cushioningor other materials for arranging the plate on a workbench or table, or,if desired, the base plate may be xedly secured to a table or bench.

Supported on the base plate I0 is an electric motor I2 with which iscoupled the usual electric extension cord I3 for placing the motor incircuit with a source of electric supply, and any suitable means may beprovi-ded to control the stopping and starting of the motor as is wellknown in the art. At I4 is shown the motor shaft upon which is clamped agrinding wheel or disk I5 by means of a fixed sleeve I6 on the motorshaft and a nut I'I. The wheel I5'is of the usual type employed in thegrinding of lenses, and this wheel operates in a tank I8 of water, awiper pad I 9 being supported at one end of the tank on a spring arm 20so as to Wipe the outer surface of the wheel to clean it or to removeforeign material therefrom, While at the same time leaving the surfacemoist as will be apparent. The wiper pad I9 may be composed of anysuitablesoft material. such for example as a sponge or a body of rubber.

The wheel I5, as seen in Fig. 1 of the drawing, rotates in a clockwisedirection and supported on the `table I0 rearwardly of the Wheel and tothe left of the motor shaft I4 is a square standard 2| in which a squaretube or rod 22 is adjustable vertically and held in different positionsof adjustment by a Wing nut 23 operating in an elongated slot 24 in thestandard 2|. The upper end of the tube or rod ,22 is split as seen at25, note Fig. 1, and passed through the split end is a bolt 26 having awing nut 2l for clamping the rod 28 of a gage plate 29 in the upper endportion of the adjustable member 22 so that the position of the gageplate 29-may-be adjusted transversely with respect to the surface of thewheel I5 to gage the radial depth of a grinding operation to beperformed in a workpiece.

It will be understood that the vertical adjustment of the member 22 willadjust theinner edge 29a of the plate 29 with respect to the peripheryof the wheel to conform therewith, and also to maintain the two surfacesspaced apart so as to provide free rotation of the wheel I5, Thisvertical adjustment will also compensate for the wear on the wheel aswill be apparent.

At 30 is shown a workpiece supporting table arranged upon suitablesupports 3|, the inner end 32 of the table being lower than the outerend thereof and being recessed'to receive the wheel I so as to permitthe free passage ofthe wheel through the recess or notch in the table,while at the same time forming a support for the workpiece at both sidesof the wheel, as will appear from a consideration of the width of thetable 30, as seen in Fig. 2 of the drawing.

Supported upon the motor I2 is a bracket 33 for supporting a water drippipe 34 to be arranged above the wheel I5 to supply water to the surfacethereof prior to grinding a workpiece arranged upon the table 30. Theinward inclination of the table will cause any water that may collectthereon to drop inwardly in the direction of the tank I8. A suitablevalve 35 will be provided in the pipe 34 for regulating the water supplythereto.

I also preferably provide a hood 3B arranged upon the upper portion ofthe motor where lthe shaft I4 enters the motor, so as to form aprojecting shield which will prevent any of the grindings from enteringthe motor to cause damage thereto. This hood is open at the bottomsurface thereof so as to provide free circulation of air to cool themotor in the usual way.

To illustrate one use and adaptation of the invention, I have shown, inFigs. 3 and 4 of the drawing, parts of any eye-glass lens 38. In Fig. 3of the drawing I have indicated the result of two different operationsperformed on a lens having a series of angularly arranged peripheralwalls 39. At this time, it will be understood that the use of myinvention is not limited to any particular shape of lens; the specificshowing in the drawing is only for illustrative purposes.

At the left of Fig. 3 one of the peripheral edge portions of the lens isground on two surfaces to form a reduced flange portion 40, which is ofless thickness than the remainder of the adjacent portion of the lens, agroove being formed on opposed side surfaces of the lens as seen at 4Iin Fig. 4 of the drawing. In this connection, it Will be understood thatonly one of the grooves 4I need be employed, and this may be arranged oneither surface of the lens in accordance with the teaching in saidearlier application.

To adapt the lens for the use as taught in said earlier application, theend portions 40a of the flange 4D, as seen at the left of Fig. 3 of thedrawing, must be cut away or notched as seen at 42 at the right of Fig.3 of the drawing so that the resulting flange 40 is of less length thanthe adjacent portion of the lens so as to form shoulders 43 at the endsof the flange 4I). The nicking or notching operation is performed bylaying the lens upon the table 3 and moving the portions 40a to beremoved over the corners of the grinding wheel I5 as will be apparent.

Where undercut shoulders are required rather than the perpendicular orrectangular corners, special forms of grinding wheels will be employed.

It will of course be understood that the adjustment of the gage plate 29will govern the radial depth of the cut to be performed in the lens toregulate the height of the protruding flange 40. In grinding a lens witha single grinding wheel,

as shown in Figs. 1 and 2, the peripheral edge is held against the gageplate while the lens is supported upon the periphery of the grindingwheel and rocked back and forth in order to produce a straight linecontour at opposite sides of the resulting flange 4U, and the thicknessof the cut formed at either or both side surfaces of the lens will begaged by the operator.

It will be understood that in applying my improved method to eye-glassesof prescription specication, the frames or other accessories applied tothe lens must be made to suit lenses of different kinds and classes and,therefore, the skill of a mechanic in performing the different grindingoperations must be depended upon to suit the hardware or frameconstruction which has been selected, the latter being standardized tocertain degree. However, in the mass production of lenses, such forexample as Sun-glasses and the like, it will be understood that thevarious operations performed on the lenses may be standardized and insuch cases suitable gages will be provided for regulating the differentoperations to be performed, that is to say, in addition to the gage asat 29.

My invention relates, as will be apparent, to the grinding of lenses ofvarious kinds and classes to adapt the same for what might be termedSpecial mounting or detachable mounting in suitable supports or frameparts, and in referring to lenses, I of course mean a transparent bodyof any type or kind which need not necessarily be glass, and which maybe used for any purpose, such for example as in the production of watchcrystals.

My present invention may be adapted for the construction of Specialcrystals for firm or positive mounting in watch-cases or irregular orspecial designs to prevent displacement of the crystal therefrom.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent, is:

l. A grinding apparatus for grinding the peripheral edges of a lens,said apparatus comprlsing a base plate, an electric motor on said plate,a grinding wheel driven by said motor, a gage plate arrangedperpendicularly to the axis of said wheel and extending along theperiphery of the wheel, in close proximity thereto, for an extentmaterially less than one-quarter of the periphery of said wheel, meansindependent of the wheel and its mounting for adjusting said gage platein its entirety relatively to the peripheral surface of the wheel toadjust said gage plate toward and from and transversely of the surfaceof the wheel, the edge portion of the gage plate adjacent the peripheryof the Wheel being curved to conform substantially to the contour of thesurface of the wheel, and said adjustable means including means torotatably adjust the gage plate in maintaining the curved edge of thegage plate in substantial parallelism to the surface of the wheel.

2. A grinding apparatus for grinding the peripheral edges of a lens,said apparatus comprlsing a drivengrinding wheel mounted on a SuitableSupport, a gage plate independently mounted on said support andadjustable relatively thereto and to said grinding wheel, the means formounting said gage plate comprising a telescoping standard adapted forvarying the height of said plate above said support, the upper extremityof said standard having transversely arranged clamping means, said gageplate having one edge thereof curved to closely conform to the contourof said Wheel, said gage plate having secured to one surface thereof acylindrical mounting rod protruding from said plate at a pointsubtantially centrally thereof, said rod being engaged by the clampingmeans of said standard, and providing free transverse and rotaryadjustment of said plate thereby providing means for adapting the gageplate to the contour of the Wheel.

3. In a grinding apparatus for use in forming grooves along peripheraledges of a lens, a driven grinding Wheel, an adjustable gage means forcontrolling said grinding operation, said gage means comprising astandard extensible vertically with respect to said Wheel, atransversely extending clamping means at the upper extremity of saidstandard, a transverse rod slidably and rotatably engaged by saidclamping means, and an elongated plate member secured to one end cf saidrod and arranged in alinement with the periphery of said wheel, the edgeof said plate adjacent said Wheel being curved to closely conform to theperipheral contour thereof, the axisof said rod protruding from a pointsubstantially centrally of said plate whereby rotatable adjustment ofsaid rod Will facilitate adjustment of the curved edge of said plate tothe maximum degree of conformity with the peripheral surface of saidwheel.

4. An apparatus for grinding grooves in the peripheral edge of a lenscomprising a motor having an extending shaft, a grinding Wheel Securedto said shaft and rotated thereby, a lens` gaging unit adjustable withrespect to the periphery of said grinding wheel, said unit comprisingrelatively adjustable parts arranged in spaced relation to the shaft ofthe motor and inwardly with respect to the periphery of said grindingwheel, a backing plate adjustable in one of said first named parts in adirection parallel to the axis of said shaft tol gage the position ofsaid plate with respect to one side surface ofthe grinding-Wheel, saidrst named parts being adjustable to move said plate toward and from theperiphery of the grinding wheel, and other means adjusting said plate toaline -one edge thereof with respect to the peripheral surface of theWheel.

REINHARDT FREDERICK METZGER.

